docs: extensive backup documentation

docs/site/guides/backups/minimal-example.md

@@ -0,0 +1,63 @@
+In this guide we will explain how to install a simple peer-to-peer backup system through the inventory. Such that machines will backup it's state to other machines in the clan, ensuring redundancy and data safety.
+
+
+### What is BorgBackup?
+
+BorgBackup is a powerful and efficient backup solution designed for secure and space-efficient backups. It offers features such as:
+
+- **Deduplication**: Saves storage space by avoiding duplicate data.
+- **Encryption**: Ensures backups are secure and authenticated.
+- **Compression**: Supports multiple compression algorithms like lz4, zstd, zlib, and more.
+- **FUSE Mounting**: Allows backups to be mounted as a file system.
+- **Cross-Platform**: Works on Linux, macOS, BSD, and more.
+- **Open Source**: Licensed under BSD and supported by an active community.
+
+
+While this guide uses BorgBackup, you can also use other backup services supported by Clan, depending on your requirements.
+
+
+### Example Setup
+
+In this example, we configure a backup system with three machines: `bob`, `jon`, and `alice`. The `bob` and `jon` machines will periodically back up their state folders to `alice`. The backups are encrypted for security.
+
+
+
+```nix
+inventory.instances = {
+  borgbackup = {
+    module = {
+      name = "borgbackup";
+      input = "clan-core";
+    };
+    roles.client.machines = {
+        "bob" = { };
+        "jon" = { };
+    };
+    roles.server.machines = { 
+        "alice" = { };
+    };
+  };
+};
+```
+
+
+## Roles
+
+In a Clan Service, roles define how machines participate in the backup system. Each role applies specific Nix configurations to the machine, enabling flexibility and scalability in your backup setup.
+
+- **Client**: These machines create backups and send them to designated destinations. Clients can be configured to back up to multiple destinations, ensuring redundancy and reliability.
+
+- **Server**: These machines act as repositories, receiving and securely storing backups from client machines. Servers can be dedicated backup nodes within your clan network, providing centralized storage for all backups.
+
+
+## Backup destinations
+
+This service allows you to perform backups to multiple `destinations`.
+Destinations can be:
+
+- **Local**: Local disk storage
+- **Server**: Your own borgbackup server (using the `server` role)
+- **Third-party services**: Such as Hetzner's Storage Box
+
+
+However, if BorgBackup does not meet your needs, you can implement your own backup clan service.